MXenes: Versatile 2D materials with tailored surface chemistry and diverse applications

MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,etc.This review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional groups.The review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group impacts.The properties of MXenes are influenced by their synthesis,which can be fluorine-based or fluorinedependent.Fluorine-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVD),alkaline etching,Lewis acid-based etching,etc.These techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,etc.on the MXenes surface,depending on the synthesis method used.Properties of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is explored.The review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,etc.Finally,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel applications.The review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.

Exploration of Ideological and Political Materials for the Course of Inorganic and Analytical Chemistry for Environmental and Ecological Engineering Major

Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing the role of collaborative education.In order to realize the seamless integration of inorganic and analytical chemistry courses and ideological and political education,this paper summarizes the current situation of ideological and political research on inorganic and analytical chemistry courses in three major databases in China(VIP,CNKI and Wanfang),and sorts out the knowledge points,ideological and political elements and educational goals according to the content of the course chapters,to provide a basic guarantee for the ideological and political education construction of the course.

Identified the hydrochemical and the sulfur cycle process in subsidence area of Pingyu mining area using multi-isotopes combined with hydrochemistry methods

Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.

基于文化自信的中外合作办学学科基础课“General Chemistry”课程思政建设探索与实践

“General Chemistry”是面向中外合作办学工科专业学生开设的一门学科基础课。为了提升教学质量,课程引入国外经典教材,在教学过程中面临外来文化的冲击和文化自信缺失的风险。因此,必须通过“General Chemistry”课程思政教学提升学生对自身文化的深度认同。本文中,“General Chemistry”课程思政建设坚持文化自信理念,积极挖掘中国思政元素,将中外思政元素合理融入到教学的每一个环节,不断助推课程思政教学内涵式发展,打造课程思政高效课堂,取得了较好的育人成效。

国外化学原理教材介绍——以Zumdahl的Chemistry(10th edition)为例

Zumdahl夫妇和DeCoste合著的Chemistry是一本在国内外广受赞誉的化学原理类教材。本文以此教材为例,介绍了国外化学原理类的教材。Chemistry这本教材内容既有广度同时也具有深度,具有可读性强、适用面广和拓展性强的特点。教材编写紧扣其培养学生化学思维和知识应用能力的基本理念,在内容和形式设计上运用了多种策略培养学生分析解决问题的能力和批判性思维能力。

国外无机化学教材的研究——以Housecroft&Sharpe的Inorganic Chemistry(5th edition)为例

Catherine Housecroft和Alan G.Sharpe合著的Inorganic Chemistry是一本经历了时间检验的经典教材,其内容涵盖了无机化学的基础原理、元素化学、生物无机化学以及这些知识在催化、工业生产和材料等领域的应用。本文希望通过对该教材的介绍及其与国内教材的编写内容和排版等的对照分析,为国内无机化学的教材编写提供一些有价值的参考,同时为从事无机化学教学的教师提供一个选择参考教材的选项。

Intrinsic Self-Healing Chemistry for Next-Generation Flexible Energy Storage Devices

The booming wearable/portable electronic devices industry has stimulated the progress of supporting flexible energy storage devices.Excellent performance of flexible devices not only requires the component units of each device to maintain the original performance under external forces,but also demands the overall device to be flexible in response to external fields.However,flexible energy storage devices inevitably occur mechanical damages(extrusion,impact,vibration)/electrical damages(overcharge,over-discharge,external short circuit)during longterm complex deformation conditions,causing serious performance degradation and safety risks.Inspired by the healing phenomenon of nature,endowing energy storage devices with self-healing capability has become a promising strategy to effectively improve the durability and functionality of devices.Herein,this review systematically summarizes the latest progress in intrinsic self-healing chemistry for energy storage devices.Firstly,the main intrinsic self-healing mechanism is introduced.Then,the research situation of electrodes,electrolytes,artificial interface layers and integrated devices based on intrinsic self-healing and advanced characterization technology is reviewed.Finally,the current challenges and perspective are provided.We believe this critical review will contribute to the development of intrinsic self-healing chemistry in the flexible energy storage field.

Integrated interface configuration by in-situ interface chemistry enabling uniform lithium deposition in all-solid-state lithium metal batteries

All-solid-state lithium metal batteries(ASSLMBs)are considered as one of the ultimate goals for the development of energy storage systems due to their high energy density and high safety.However,the mismatching of interface transport kinetics as well as interfacial instability induces the growth of lithium dendrite and thus,leads to severe degradation of battery electrochemical performances.Herein,an integrated interface configuration(IIC)consisting of in-situ generated Li I interphase and Li-Ag alloy anode is proposed through in-situ interface chemistry.The IIC is capable of not only regulating charge transport kinetics but also synchronously stabilizing the lithium/electrolyte interface,thereby achieving uniform lithium platting.Therefore,Li||Li symmetric cells with IIC achieve a critical current density of up to 1.6 mA cm^(-2)and achieve stable cycling over 1600 hours at a high current density of 0.5 mA cm^(-2).Moreover,a high discharge capacity of 140.1 mA h g-1at 0.1 C is also obtained for the Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)full battery with a capacity retention of 65.6%after 300 cycles.This work provides an effective method to synergistically regulate the interface transport kinetics and inhibit lithium dendrite growth for high-performance ASSLMBs.

Recent Progress in Atmospheric Chemistry Research in China: Establishing a Theoretical Framework for the “Air Pollution Complex”

Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.

Single-atom electrocatalysts for lithium-sulfur chemistry:Design principle,mechanism,and outlook

Lithium-sulfur batteries(LSBs)have been regarded as one of the promising candidates for the next-generation“lithium-ion battery beyond”owing to their high energy density and due to the low cost of sulfur.However,the main obstacles encountered in the commercial implementation of LSBs are the notorious shuttle effect,retarded sulfur redox kinetics,and uncontrolled dendrite growth.Accordingly,single-atom catalysts(SACs),which have ultrahigh catalytic efficiency,tunable coordination configuration,and light weight,have shown huge potential in the field of LSBs to date.This review summarizes the recent research progress of SACs applied as multifunctional components in LSBs.The design principles and typical synthetic strategies of SACs toward effective Li–S chemistry as well as the working mechanism promoting sulfur conversion reactions,inhibiting the lithium polysulfide shuttle effect,and regulating Li+nucleation are comprehensively illustrated.Potential future directions in terms of research on SACs for the realization of commercially viable LSBs are also outlined.

EXPERIMENTAL GEOCHEMISTRY STUDY ON GOLD IN WATER-ROCK REACTION UNDER THERMAL FLUID SYSTEM AT MESO-LOW TEMPERATURE

Based on the knowing geochemical characteristics of wall rock in the Mobin gold deposit and composition of fluid inclusion in ore,water rock experiments were carried out, important achievements are acquired as following: Gold is mainly derived from the ore bearing wall rock,i.e., a series of epimetamorphic clastic gritstone, sandy slate, and tuffaceous slate in the Wuqiang Banxi Formation, Wuqiangxi Group. In thermal system with middle low temperature chlorine gold may be derived form stable complex ions, so it is quite important in gold metallogenic process. Sulphur and chlorine perform as the major negative ions throughout the gold activation and migration movement. The concentration of sulphur and chlorine ions, pH value and temperature are of deciding significance for gold activation, migration and precipitation.

Differences in CO_(2)-Water-Rock Chemical Reactions among ’Sweet Spot’ Reservoirs:Implications for Carbon Sequestration

The Lucaogou Formation,located in the Jimsar Sag,Junggar Basin,NW China,has great potential for shale oil resources.In the process of CO_(2)-EOR(CO_(2) enhance oil recovery),mineral dissolution,precipitation and transformation,leading to the local corrosion or blockage of reservoirs,have a significant influence on recovery.In this study,a combination of high-temperature and high-pressure laboratory experiments and coupled temperature/fluid-chemistry multifield numerical simulations are used to investigate CO_(2)-water-rock reactions under various reservoir conditions in the upper and lower ’sweet spots’,to reveal the mechanisms underlying CO_(2)-induced mineral dissolution,precipitation and transformation.In addition,we quantitatively calculated the evolution of porosity over geological timescales;compared and analyzed the variability of CO_(2) transformation in the reservoir under a variety of temperature,lithology and solution conditions;and identified the main factors controlling CO_(2)-water-rock reactions,the types of mineral transformation occurring during long-term CO_(2) sequestration and effective carbon sequestration minerals.The results demonstrate that the main minerals undergoing dissolution under the influence of supercritical CO_(2) are feldspars,while the main minerals undergoing precipitation include carbonate rock minerals,clay minerals and quartz.Feldspar minerals,especially the initially abundant plagioclase in the formation,directly affects total carbon sequestration,feldspar-rich clastic rocks therefore having considerable sequestration potential.

Geochronology,Geochemistry,Fluid Inclusion and C,O Isotope Compositions of Calcite Veins in the Paleogene of the Jiangling Basin,South China:Implications for Fluid Evolution and Brine Potash Mineralization

Deep-seated potassium-rich brines were identified in the Jiangling Basin,South China.Although magmatichydrothermal sources have been proposed,the relationship between brine-type potash mineralization and volcanism remains unclear.In this study,U-Pb geochronology,geochemistry,fluid inclusion and C-O isotopic compositions of hydrothermal vein minerals in the Jiangling Basin are examined.Laser ablation U-Pb dating of calcite veins indicates that the ages are slightly younger than the formation age of the Balingshan basalt.Fluid inclusions in hydrothermal minerals show medium–low homogenization temperatures(160–220℃)and low salinities(0.14 to 4.9 wt%NaCl eqv.)and densities(0.882–0.944 g/cm^(3)).The liquid compositions of fluid inclusions in calcite veins from sedimentary strata have higher contents of potassium,compared with those from basalt.The coupled negativeδ^(13)CPDB(-10.3‰to-8.0‰)and positiveδ^(18)OSMOW(17.4‰to 20.7‰)values imply that calcite precipitation resulted from CO_(2)degassing of the basaltic magmatic fluids,as indicated by the gas composition of these inclusions in hydrothermal minerals.Rare earth element patterns indicate that water-rock interaction between hydrothermal fluids and sedimentary wall rocks contributed to the calcite precipitation in sedimentary strata.It is proposed that high-temperature water-rock interaction between magmatic fluids and sedimentary strata resulted in the potassium enrichment in fluids,interpreted as one of the sources of potassium-rich brines in the Jiangling Basin.

Green Chemistry Allometry Test of Microwave-Assisted Synthesis of Transition Metal Nanostructures

Microwave irradiation is considered an important approach to Green Chemistry, because of its ability to rapidly increase the internal temperature of polar-organic compounds that lead to synthesis times of minutes rather than hours when compared to conventional thermal heating. This works describes a dual allometry test for the discrimination between the solvents and reagents used in the microwave-assisted synthesis of transition metal (zinc oxide, palladium silver, platinum, and gold) nanostructures. The test is performed in log-log process energy phase-space projection, where the synthesis data (kJ against kJ·mol-1) has a power-law signature. The test is shown to discriminate between recommended Green Chemistry, problematic Green Chemistry, and Green Chemistry hazardous solvents. Typically, recommended Green chemistry exhibits a broad y-axes distribution within an upper exponent = 1 and lower exponent = 0.5. Problematic Green Chemistry exhibits a y-axes narrower distribution with an upper exponent = 0.94 and lower exponent = 0.64. Non-Green Chemistry hazardous data exhibits a further narrowing of the y-axes distribution within upper exponent = 0.87 and lower exponent = 0.66. In all three cases, the y-axes is aligned to original database power-law signature. It is also shown that in the x-axes direction (process energy budget) the grouped order of magnitude decreases from four orders for recommended Green Chemistry solvent and reagent data, through two orders for non-Green Chemistry hazardous material and down to one order for problematic Green Chemistry.

Petrographical and mineral chemistry evidence to delineate the source/sources of the Central Indian Ocean Basin pumices

We present data pertaining to mineral assemblages and composition of the Central Indian Ocean Basin(CIOB)pumices.Eight groups of pumices were identified considering the presence of phenocrysts of plagioclase,clinopyroxene,orthopyroxene,hornblende and biotite together with the occurrence of quartz and glass.Pigeonite,fayalite and ulvospinelare reported for the first time from these pumices.In the eight groups,the modal percentage of the constituents are phenocrysts 3%to 19%(avg 9.6%),silicic glass 33%to 54%(avg 43%)and the rest is vesicles.Based on the above factors we have identified the possible sources of the CIOB pumices.The mineral compositions of plagioclase,pyroxenes,and biotite of the CIOB pumices were compared with those of Krakatau and Toba.Most of the plagioclase and pyroxene compositions resemble the Haranggoal Dacite Tuff of Toba and Krakatau.Considering the mineral assemblages and compositions,there are pumices which do not correlate to any of the above eruptions and are probably from yet unidentified source/sources.These sources could either be from nearby terrestrial volcanoes or intraplate seamounts present in the CIOB.In a global context,it is viable that petrological characteristics could be used as initial criteria to determine the source of pumices that occur at abyssal depths in the world ocean.

Simultaneous regulation on coordination environment and interfacial chemistry via taurine for stabilized Zn metal anode

Aqueous Zn-ion batteries(AZIBs)are the potential options for the next-generation energy storage scenarios due to the cost effectiveness and intrinsic safety.Nevertheless,the industrial application of AZIBs is still impeded by a series of parasitic reactions and dendrites at zinc anodes.In this study,taurine(TAU)is used in electrolyte to simultaneously optimize the coordination condition of the ZnSO4electrolyte and interfacial chemistry at the anode.TAU can preferentially adsorb with the zinc metal and induce an in situ stable and protective interface on the anode,which would avoid the connection between H_(2)O and the zinc metal and promote the even deposition of Zn^(2+).The resulting Zn//Zn batteries achieve more than 3000 hours long cyclic lifespan under 1 mA cm^(-2)and an impressive cumulative capacity at 5 mA cm^(-2).Moreover,Zn//Cu batteries can realize a reversible plating/stripping process over 2,400cycles,with a desirable coulombic efficiency of 99.75%(1 mA cm^(-2)).Additionally,the additive endows Zn//NH_(4)V_(4)O_(10)batteries with more stable cyclic performance and ultrafast rate capability.These capabilities can promote the industrial application of AZIBs.

Revealing the effect of electrolyte coordination structures on the intercalation chemistry of batteries

In-depth understanding of the electrolyte-dependent intercalation chemistry in batteries through direct operando/in situ characterizations is crucial for the development of the high-performance batteries.Herein,taking the Al/graphite battery as a model system,the effect of electrolyte coordination structure on the intercalation processes has been investigated over the batteries with either 1-hexyl-3-methylimidazolium chloride(HMICl)-AlCl_(3) or 1-ethyl-3-methylimidazolium chloride(EMICl)-AlCl_(3) ionic liquid electrolyte using operando X-ray photoelectron spectroscopy(XPS)and X-ray diffraction.With a weaker anion-cation interaction in HMI-based electrolyte,the XPS-derived atomic ratio between cointercalated N and intercalated Al is 0.9,which is lower than 1.6 for EMI-based electrolyte.Attributed to the additional de-solvation process,the batteries with the HMI-based electrolyte show a lower ionic diffusion rate,capacity,and cycling performance,which agree with the operando characterization results.Our findings highlight the critical role of the electrolyte coordination structure on the(co-)intercalation chemistry.

Depth profiling of arsenian pyrite in Carlin-type ores through wet chemistry

Enrichment of As and Au at the overgrowth rims of arsenian pyrite is a distinctive feature of Carlin-type gold ores.Revealing distribution of such key elements in high resolution is of fundamental importance yet often proves challenging.In this study,repeated non-oxidative acid etching of ore samples from Shuiyindong gold deposit was applied to enable elemental depth profiling of goldbearing arsenian pyrite grains.ICP-OES and AAS were used to determine the dissolved Fe,As,and Au concentrations in each of the etching solutions,and XPS was carried out to exam the etched mineral surfaces.In contrast to conventional ion beam etching that may cause substantial sample damage,our acid etching method does not seem to significantly alter the composition and chemical state of the samples.The etched depths directly converted from the measured elemental concentrations can reproducibly reach a very high resolution of~1 nm,and can be conveniently controlled through varying the etching time.While the Fe and As depth profiles consistently reflect the surface oxidation property of arsenian pyrite,the Au profile displaying an obvious upward trend reveals the ore fluid evolution at the late stage of mineralization.Based on our experimental results,we demonstrate that our wet chemistry method is capable of effective depth profiling of gold ore and perhaps other geological samples,with advantages surpassing many instrumental techniques including negligible sample damage,nanoscale resolution as well as isotropic etching.

Rechargeable Na-MnO_(2) battery with modified cell chemistry

High voltage,high energy density,nominal cycle life,and low cost are the most critical requirements of rechargeable batteries for their widespread energy storage applications in electric vehicles and renewable energy technologies.Na-MnO_(2) battery could be a low-cost contender,but it suffers extensively from its low cell voltage and poor rechargeability.In this study,we modified the conventional cell structure of Na-MnO_(2) battery and established altered cell chemistry through a hybrid electrochemical process consisting of Na striping/plating at the anode and Zn^(2+) insertion/de-insertion along with MnO_(2) dissolution/deposition at the cathode.After the modification,Na-MnO_(2) battery exhibits a discharge capacity of 267.10 mA h/g and a cell voltage of 3.30 V(vs.Na/Na^(+)),resulting in a high specific energy density of 881.43 Wh/kg.After 300 cycles,the battery retains 98% of its first-cycle discharge capacity with100% coulombic efficiency.Besides,Na metal-free battery assembled using sodium biphenyl as a safer anode also delivers an excellent energy density of 810.0 Wh/kg.This work could provide a feasible method to develop an advanced Na-MnO_(2) battery for real-time energy storage applications.

Tunable vacancy defect chemistry on free-standing carbon cathode for lithium-sulfur batteries

The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of ion/electron-conductive and defect-rich networks on the threedimension carbon cathode,leading to its tunable activity for both relieving the shuttle phenomenon and accelerating the sulfur redox reaction kinetics.As expected,the defective carbon cathode harvests a high rate capacity of 1217.8 mAh g^(-1)at 0.2 C and a superior capacity retention of61.7%at 2 C after 500 cycles.Even under the sulfur mass loading of 11.1 mg cm^(-2),the defective cathode still holds a remarkable areal capacity of 8.5 mAh cm^(-2).